Science
Science

How Many Hours of Sleep Do You Need?

Written by: Alison Deshong

Updated March 30, 2021

 

Medical experts still don’t completely understand why we evolved to sleep (1). But, after decades of research, one thing is crystal clear: sleep is paramount to short-term and long-term health (2). If you’ve ever wondered how much sleep you really need each night to stay healthy, we’ll put your question to rest with a discussion about the recommended hours of sleep from leading sleep experts.

How Much Sleep Do I Need?

When trying to figure out the optimal amount of sleep you need, it’s best to consult with the experts. The leading sleep research organizations in the United States, such as the National Sleep Foundation, the American Academy of Sleep Medicine, and the Sleep Research Society, publish recommendations based on the most recent clinical research.

The recommendations for how many hours of sleep a person needs over a 24-hour period vary by age. As shown below, needs differ for newborns (3), infants (4), adolescents, and adults (5). For younger children, total sleep needed includes daytime naps.

Age Recommended Hours of Sleep
Infants (4-12 months) 12-16 hours
Toddlers (1-2 years) 11-14 hours
Preschool Aged Children (3-5 years) 10-13 hours
School Aged Children (6-12 years) 9-12 hours
Teens (13-18 years) 8-10 hours
Adults (18-60 years) 7-9 hours
Older Adults (over 60 years) 7-8 hours

How Do My Sleep Needs Change With Age?

Many believe they can get away with pulling all-nighters or not prioritizing sleep in their younger years. However, sleep is a crucial component of your physical health and mental wellbeing, no matter your age. Adolescents and young adults are just as vulnerable to the effects of sleep loss (6) as older adults.

As you age, you may notice that the way you sleep starts to shift. Notable changes in sleep patterns with aging (7) include:

  • Feeling tired earlier in the evening
  • Waking up earlier in the morning
  • Shortened sleep duration at night
  • More daytime naps
  • More nightly awakenings
  • More time spent awake during the night

Despite these differences in sleep patterns, the hours you need to sleep in a 24-hour period for optimal health are about the same whether you’re age 20 or 80. There’s a common misconception that you need significantly less sleep as you grow old, but adults over the age of 60 still need seven to eight hours of sleep.

Is Seven Hours of Sleep Enough?

Seven hours of sleep every night represents the lower end of what experts recommend, but it’s still within the healthy range. Keep in mind that everyone is unique, and genetics can play an important role (8) in our individual response to sleep. While some people may feel fully rested after getting seven hours of sleep, you may require a full nine hours.

Also, keep in mind that seven hours is the minimum recommendation for the amount of sleep you need. To get a full seven hours of sleep, you’ll likely need to spend a bit longer in bed to make up for the time it takes you to fall asleep and any nighttime awakenings.

Is Four Hours of Sleep Enough?

Although everyone is different, four hours is not enough sleep for the vast majority of kids and adults. Certain genetic mutations (9) may cause some people to need much less than the standard seven to nine hours of sleep, but these mutations are incredibly rare. Even if you think you function well on only four hours of sleep, you’re probably not very good at judging how much inadequate sleep affects your health (10).

Can I Make Up for Lost Sleep?

Around one-third of adults in the United States (11) report receiving less than the recommended seven hours of sleep each night. If you’re someone who frequently misses out on a full night’s rest, you’ve probably wondered whether you can pay down your sleep debt by sleeping more in the future.

Sleeping in on the weekends is one strategy to make up for lost sleep throughout the work week. This approach may even improve mortality outcomes (12) when compared to running a sleep deficit on both weekdays and weekends. Although using the weekends to catch up on missing sleep is better than never making up for lost sleep, the practice of deprivation and catchup can still negatively affect the body. The healthiest option is to receive the recommended amount of sleep each 24-hour period.

If you have trouble getting enough sleep at night, you can also try napping to give yourself a more immediate jolt of energy during the week. Even a quick nap can help you feel more rejuvenated and improve several of the cognitive abilities lost to sleep deprivation (13).

Tricks like playing weekend catch up and napping are good in a pinch when you have one night or even a whole week of bad sleep. However, these tricks may not be enough to stave off the effects of chronic sleep deprivation (14). Instead, you’ll need to enact a plan to improve the quality and quantity of your sleep for the long haul.

Can I Sleep Too Much?

Getting enough sleep is important, but that doesn’t mean more is always better. In fact, there may be a correlation between higher mortality rates (15) and getting more than the recommended seven to nine hours of sleep.

However, the medical community still hasn’t come to a consensus on whether or not more sleep can harm you. Instead, longer than average sleep duration may be a marker rather than a cause (16) of poor health.

If you find yourself tired even after a full night of sleep, you may have an underlying condition that’s interfering with your sleep quality and causing tiredness. To rule out any serious medical conditions, such as sleep apnea, consider starting a sleep journal to record your sleep patterns and habits, and then discuss the results with your doctor.

Sleep is a free and easy way to make sure you stay healthy and sharp into old age, but don’t let yourself get lost in the details. If you’re an adult, all you need to remember is the magic range of seven to nine hours of sleep every night for better health.

 

References

 

  1. https://pubmed.ncbi.nlm.nih.gov/26447948/ Accessed on March 25, 2021.
  2. https://www.merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/sleep-disorders/overview-of-sleep Accessed on March 25, 2021.
  3. https://pubmed.ncbi.nlm.nih.gov/29073412/ Accessed on March 25, 2021.
  4. https://pubmed.ncbi.nlm.nih.gov/27250809/ Accessed on March 25, 2021.
  5. https://pubmed.ncbi.nlm.nih.gov/26039963/ Accessed on March 25, 2021.
  6. https://pubmed.ncbi.nlm.nih.gov/28974591/ Accessed on March 25, 2021.
  7. https://pubmed.ncbi.nlm.nih.gov/29412976/ Accessed on March 25, 2021.
  8. https://pubmed.ncbi.nlm.nih.gov/28325617/ Accessed on March 25, 2021.
  9. https://pubmed.ncbi.nlm.nih.gov/31473062/ Accessed on March 25, 2021.
  10. https://pubmed.ncbi.nlm.nih.gov/27263430/ Accessed on March 25, 2021.
  11. https://www.cdc.gov/sleep/data_statistics.html Accessed on March 25, 2021.
  12. https://pubmed.ncbi.nlm.nih.gov/29790200/ Accessed on March 25, 2021.
  13. https://pubmed.ncbi.nlm.nih.gov/16796222/ Accessed on March 25, 2021.
  14. https://pubmed.ncbi.nlm.nih.gov/30827911/ Accessed on March 25, 2021.
  15. https://pubmed.ncbi.nlm.nih.gov/17625932/ Accessed on March 25, 2021.
  16. https://pubmed.ncbi.nlm.nih.gov/17854737/ Accessed on March 25, 2021.